High-pressure discharge lamps to which the present invention relates are frequently used with arc discharge tubes of quartz glass, including a fill of a metal halide, retained within an outer envelope. Lamps of this type having a power rating of between 100 to 1000 W require a stable, sturdy holder mount which retains the discharge vessel in position within an outer bulb. Different thermal coefficients of expansion of the materials and different thermal expansions of the various components of the lamp cause problems. Additionally, such lamps may be subjected to shock or vibration, and rough handling, particularly during shipment. Deformation of the holder structure or misplacement of the arc discharge tube upon being subjected to such shocks or to vibration must be avoided. Breakage of the lamp bulb, and especially of the arc tube, likewise should be avoided; thus the arc tube should be reliably held within the vessel while, however, absorbing external shocks.
It has been proposed to use double-ended arc tubes having pinch or press seals at the respective ends. These pinch or press seals are secured to the support structure within the lamp by placing a sheet metal collar around one or both of the pinch or press seals and securing the collars to the support structure within the lamp, which is also secured to the base thereof.
Use of collars permits guidance of the discharge vessel in the axial position within the lamp, however permits expansion only in axial direction. A lateral deflection of the lamp, for example by a blow or impact against the lamp as a whole, is not possible. Guide elements using collars are shown, for example, in the referenced U.S Pat. No. 4,376,259, Rothwell et al, as well as in German 30 06 846, Kuus et al. It has been found that the use of such collars interferes with automated manufacture of the lamps and economical assembly thereof, and, additionally, does not provide the required resistance of the lamp as a whole to impacts thereagainst which may arise, for example upon shipment of the lamp when a package of lamps, for example, is thrown on a transport belt or the like.